For an organic light-emitting diode (OLED) display device, a light-emitting material is driven by a current to emit light autonomously. Since the light-emitting material in the OLED display device is sensitive to temperature, air and water, good packaging is very important for the lifetime and image quality of the OLED display device. There are many technologies for packaging the OLED display device, for example, laser packaging, thin-film packaging, injection packaging, etc. The laser packaging is currently a mature technology for packaging the OLED display device, and its main operating principle is to heat and melt, in a precise and quick manner, a glass cement at a specific position between two glass substrates (one is a cover plate, while the other is a back plate on which the light-emitting material and a circuit pattern are formed) by using a laser beam, thereby to package the two substrates.
During a conventional laser sintering process, the glass cement may instantaneously be heated to a temperature of 800° C. to 1000° C. from the room temperature, and then be cooled down to the room temperature. A shrinkage stress may be accumulated inside the glass cement during the quick heating and cooling, resulting in cracks and even breakages in subsequent processes. Currently, there are substantially two methods to overcome this drawback. The first method is to reduce the shrinkage stress by decreasing thermal expansion coefficients of the glass substrates and the glass cement. The second method is to decrease a laser sintering speed. However, for the first method, the materials of the glass substrates and the glass cement will be greatly restricted, while for the second method, it is not applicable to mass production. Hence, the manufacture of OLED display device is greatly restricted by these methods.